Bunn CWT-TSR, CW-APS service manual Tank Heater

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SERVICE (cont.)

TANK HEATER

P1127.40

FIG. 12 TANK HEATER

Location:

The tank heater is located inside the tank and secured to the tank lid.

Test Procedures:

1.Disconnect the brewer from the power supply.

2.With a voltmeter, check the voltage across the black and white wires on 100 or 120 volt models or the black and red wires for 120/240 volt mod- els, 200 volt models and 240 volt models . Con- nect the brew to the power source. The indication must be:

a)120 volts ac for two wire 120 volt 15 and 20 amp models .

b)240 volts ac for three wire 120/240 volt models.

c)200 to 240 volts ac for two wire 200 or 240 volt models.

d)100 volts ac for two wire 100 volt models.

3.Disconnect the brewer from the power source.

If voltage is present as described, proceed to #4

If voltage is not present as described, refer to the Wiring Diagrams and check wiring harness.

4.Disconnect the black wire and the white wire or red wire from the tank heater terminals.

5.Check for continuity across the tank heater termi- nals.

If continuity is present as described, reconnect the wires, the tank heater is operating properly.

If continuity is not present as described, replace the tank heater.

NOTE- If the tank heater remains unable to heat, remove and inspect heater for cracks in the sheath.

Removal and Replacement:

1.Disconnect the water supply tube from the fill basin.

2.Remove the tank inlet fitting securing the fill basin to the tank lid, remove fill basin and tank inlet gasket. Set all three parts aside for reassembly.

3.On brewers with a faucet, shut off water supply to the brewer and disconnect the inlet and outlet water lines to the faucet coil assembly.

4.Disconnect the black wire on the limit thermostat from the tank heater switch. On late model brew- ers also disconnect the blue wire from the limit thermostat to the control thermostat.

5.Disconnect the black wire and the white or red wire from the tank heater terminals.

6.Remove sprayhead and the hex nut securing the sprayhead tube to the hood. Set aside for reas- sembly.

7.Remove the eight #8-32 nuts securing the tank lid to the tank.

8.Remove the tank lid with limit thermostat, spray-

head tube, tank heater, coil assembly and control thermostat w/bracket (early models only).

9Remove the two hex nuts securing the tank heater to the tank lid. Remove tank heater with gaskets and discard.

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Contents CWT-TSR Introduction WarrantyUser Notices Plumbing Requirements Electrical RequirementsElectrical Hook-Up Models CW-APS & CWT-TSEarly MO Dels W/OUT Fauc ET Plumbing RequirementsThird Type Models W/FAUCET Models CWTF-APS, CWTF-TS CWTF-TSR4A.Models CW-APS & CW-TS Initial SET-UP6A.Models CW-APS & CW-TS 8A.Models CWA-PS & CW-TSON/OFF Switch Adjusting Brew VolumesStart Switch Operating ControlsCleaning Coffee Brewing5A.Models CW-APS & CW-TS Problem Probable Cause Remedy TroubleshootingBrew cycle will not start CWT No water Must be openProblem Probable Cause Remedy TroubleshootingCWTF-TS, CWT-TSR &CWTF TSRCWTF-TSR ProblemBeverage overflows dispenser Spitting or excessive steaming Dripping from sprayheadControl Thermostat Syphon System Lime Build-up DispenserCWTF-TS, CWT-TSR, CWTF-TSR CWT-APS, CWTF-APS, CWT-TSRemove and clean lime off the tank heater. See CWT-TS, CWTF-TS, CWT-TSR CWTF-TSRBrewer is making unusal noises Tank Heater Service Component AccessContents Control Thermostat ServiceLimit Thermostat Service Control ThermostatON/OFF Switch Test Procedures Disconnect the brewer from the power source Solenoid ValveLocation Start Switch Terminals Start SwitchTank Heater Tank HeaterService Tank Heater Tank Heater Switch Tank Heater SwitchTank Heater Switch Terminals Service Tank Heater SwitchDisconnect the black and white wires to the sole- noid Service TIMEREarly ModelsOLD Style Service TimerIf voltage is as described, proceed to #7 Digital Brew Timer Late ModelsTimer Setting Service Digital Brew Timer Late Modelscont10690 10690 10690 10690 10690